<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Symbol 内置属性</title>
</head>
<body>
    <script>
        // class Person {
        //     static [Symbol.hasInstance] (param) {
        //         console.log(param);
        //         console.log(`我被用来检测类型了`);
        //     }
        // }
        // let o = {};
        // console.log(o instanceof Person)

        const arr1 = [1, 2, 3];
        const arr2 = [4, 5, 6];
        arr2[Symbol.isConcatSpreadable] = false;
        console.log(arr1.concat(arr2));
    </script>
</body>
</html>